Iraqi special operations forces advance during a field training exercise in Baghdad in May. (Sgt. Mitchell Ryan/U.S. Army)

When the Iraqi government launched an online recruitment drive for its elite counterterrorism forces in May, a startling 300,000 men applied. Of those, 3,000 passed a preliminary screening. Only about 1,000 are expected to be accepted into the rigorous joint American-Iraqi training academy, an American military trainer said.

The staggering response points to the popularity of the “Golden Division” following its high-profile role in wresting back territory from the Islamic State. But the rigorous selection process highlights the challenge of rebuilding a force that the United States says lost 40 percent of its human and military resources in the nine-month battle for the city of Mosul.

Samaher Saddam cleans the entrance of her damaged house on the west side of Mosul on July 13, 2017, a few days after the Iraqi government’s announcement of the “liberation” of the embattled city from the Islamic State. (Felipe Dana/AP)

MOSUL, Iraq — The streets of Mosul’s Old City are littered with bodies, tangled between shattered stones and remnants of the lives they left behind.

In the baking summer heat, exhausted rescue crews are now sifting through the debris of the toughest battle against the Islamic State in what became its final redoubt in the city.

As Iraqi ground troops, U.S.-led coalition jets and Islamic State militants pulverized the Old City’s winding maze of streets, thousands of civilians were caught in the crossfire.

But the area is now deserted, its inhabitants evacuated to houses, camps or prison cells across the province in recent months.

A week after Iraqi officials declared victory in Mosul, all that remains in the Old City is rubble and unknown hundreds of bodies.

A boy walks along a damaged street in west Mosul on July 13, 2017, a few days after the Iraqi government announced the “liberation” of the embattled city from Islamic State fighters. (Safin Hamed/AFP/Getty Images)

IRBIL, Iraq — A leading human rights group urged Iraqi authorities to investigate allegations of abuse against alleged Islamic State fighters and their families, after videos surfaced of detainees being beaten and executed.

Iraqi forces have arrested thousands of people in the former Islamic State stronghold of Mosul in recent months as the battle against the militants there reached its endgame.

Four videos uploaded to the Internet this week appeared to show Iraqi soldiers or federal policemen abusing suspected militants. In one video, a man is beaten before being thrown off a cliff and shot on the ground below.

Smoke plumes billow in the Old City of Mosul during the offensive by the Iraqi force to retake the city from Islamic State fighters, on Monday. (Fadel Senna/AFP/Getty Images)

After nine months of vicious street-to-street fighting to drive the Islamic State out of Mosul, it could take many years more to fully remove explosives and other munitions from one of Iraq’s most populous cities, U.S. State Department officials said.

“When I look around the world in some ways there’s nothing like Mosul that we’ve encountered.” said Stanley Brown, the director of State’s Office of Weapons Removal and Abatement. “The level of contamination though is not one of those where we’re talking weeks and months, we’re talking years and maybe decades.”

Over three years of occupation, the Islamic State mined and booby-trapped large sections of Mosul. Heavy combat has also littered the city with unexploded ordnance such as artillery shells and hand grenades. In the western reaches of the city, where the fighting was especially fierce, massive debris fields will need to be removed to clear the ground beneath.

Civilians gather on June 24 at a food distribution point in a Mosul neighborhood liberated by Iraqi security forces. (Felipe Dana/AP)

In Mosul right now, families are cheering, singing as they clutch the Iraqi flag. Drivers are blasting their horns. All because in their city, the Islamic State has been ousted.

On Monday, Iraqi Prime Minister Haider al-Abadi declared “the end of the ISIS statelet” in his country. It’s being celebrated as a major, national victory for embattled Iraq, one that has brought dancing revelers into the streets in Baghdad and fireworks over the southern city of Basra.

That’s not the story you’d get, though, if you follow the Islamic State on social media. Since it lost Mosul, the terrorist group has been working to counter “persistent narratives of its gradual defeat by characterizing its current situation as a heroic, action movie-esque last stand,” explains Rita Katz, a terrorism analyst and co-founder of the Search for International Terrorist Entities (SITE) Intelligence Group. Katz pointed to a July 10 communique that read in part: “The soldiers of the Caliphate continue to record epics until they achieve one of the two good ends, either victory or martyrdom.”

The fight to reclaim the city of Mosul from the Islamic State is one of the biggest yet against the militant group.

More than a million civilians are thought to be trapped in the city, and the already difficult battle is complicated by the uneasy mix of forces that have formed a coalition to rid the city of extremists.